Warner Bros. has announced that casting for the sixth Harry Potter film, Harry Potter and the Half-Blood Prince, is complete.

New cast members for the sixth installment, based on the best-selling novel by J.K. Rowling, include Jim Broadbent and Helen McCrory. Broadbent will play, Horace Slughorn, the new potions professor who gives Harry Potter an old Potions textbook that had once belonged to the a former student known only as “The Half-Blood Prince.” McCrory, who was originally cast to play Bellatrix Lestrange in the fifth film, but had to bow out after she became pregnant, appears in the sixth film as Narcissa Malfoy, mother to Draco, wife to Lucius, and sister to the wicked Bellatrix Lestrange (Helena Bonham Carter).

Several young newcomers will be making their feature film debuts in the film, directed by David Yates. Jessie Cave won the role of Lavender Brown, a fellow Hogwarts student who becomes Ron Weasley’s (Rupert Grint) love interest; 16-year-old Frank Dillane will a teenage Tom Riddle, who is already on the path to becoming the evil Lord Voldemort (Ralph Fiennes); and Fiennes’s 9-year-old nephew, Hero Fiennes Tiffin, will appear as a young Riddle at age 11.

Returning to their starring roles as the young wizards Harry Potter, Ron Weasley, and Hermione Granger are Daniel Radcliffe, Rupert Grint, and Emma Watson, respectively. They will be reunited with returning Harry Potter cast members, including Helena Bonham Carter, David Bradley, Robbie Coltrane, Warwick Davis, Tom Felton, Michael Gambon, Alan Rickman, Maggie Smith, Natalia Tena, Julie Walters, and David Thewlis, as well as Evanna Lynch, Matthew Lewis, and Bonnie Wright.

Screenwriter Steve Kloves, who scripted the first four installments of the film franchise, is adapting the screenplay for Half-Blood Prince.

Harry Potter and the Half-Blood Prince hits theaters on November 21, 2008.